Implementation:LMCache LMCache Load Engine Config With Overrides

Knowledge Sources	LMCache
Domains	Infrastructure, Configuration
Last Updated	2026-02-09 00:00 GMT

Overview

Concrete tool for loading and validating LMCache engine configuration provided by the lmcache library.

Description

The load_engine_config_with_overrides function is the primary entry point for creating an LMCacheEngineConfig instance. It delegates to a generic config loading utility that reads YAML files, applies environment variable overrides (all prefixed with LMCACHE_), and merges programmatic overrides. The resulting config object is validated to ensure consistency across all enabled features.

The LMCacheEngineConfig class is dynamically generated via create_config_class using a central _CONFIG_DEFINITIONS dictionary that defines all fields with types, defaults, and environment variable converters.

Usage

Import this function when initializing any LMCache deployment. It is always the first API call in any workflow. Set configuration via YAML file (pointed to by LMCACHE_CONFIG_FILE environment variable), individual LMCACHE_* environment variables, or pass a dictionary of overrides.

Code Reference

Source Location

Repository: LMCache
File: lmcache/v1/config.py
Lines: L715-L754 (LMCacheEngineConfig creation and load function)

Signature

def load_engine_config_with_overrides(
    config_file_path: Optional[str] = None,
    overrides: Optional[Dict[str, Any]] = None,
) -> LMCacheEngineConfig:
    """
    Load engine configuration with support for file, env vars, and overrides.

    Args:
        config_file_path: Optional direct path to config file
        overrides: Optional dictionary of configuration overrides

    Returns:
        Loaded and validated LMCacheEngineConfig instance
    """

Import

from lmcache.v1.config import load_engine_config_with_overrides, LMCacheEngineConfig

I/O Contract

Inputs

Name	Type	Required	Description
config_file_path	Optional[str]	No	Direct path to YAML config file. If None, reads LMCACHE_CONFIG_FILE env var
overrides	Optional[Dict[str, Any]]	No	Dictionary of configuration overrides applied last

Outputs

Name	Type	Description
return	LMCacheEngineConfig	Validated configuration instance with all fields set

Usage Examples

Via Environment Variables

import os
os.environ["LMCACHE_CHUNK_SIZE"] = "256"
os.environ["LMCACHE_LOCAL_CPU"] = "True"
os.environ["LMCACHE_MAX_LOCAL_CPU_SIZE"] = "5"

from lmcache.v1.config import load_engine_config_with_overrides
config = load_engine_config_with_overrides()

Via YAML File

import os
os.environ["LMCACHE_CONFIG_FILE"] = "/path/to/config.yaml"

from lmcache.v1.config import load_engine_config_with_overrides
config = load_engine_config_with_overrides()

Via Explicit Path and Overrides

from lmcache.v1.config import load_engine_config_with_overrides
config = load_engine_config_with_overrides(
    config_file_path="/path/to/config.yaml",
    overrides={"chunk_size": 512, "local_cpu": True}
)

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